When, for example, a semiconductor component or a flat panel display is manufactured, a substrate liquid processing apparatus is used to perform a processing, such as etching, on a substrate such as a semiconductor wafer or a liquid crystal substrate using a processing liquid such as an etching liquid.
For example, a substrate liquid processing apparatus disclosed in Japanese Patent Laid-Open Publication No. 2013-093478 performs a process of immersing a substrate in a processing liquid (an etching liquid: a phosphoric acid aqueous solution) stored in a processing bath, and etching a silicon nitride film formed on the surface of the substrate.
In the substrate liquid processing apparatus, a phosphoric acid aqueous solution obtained by diluting phosphoric acid with pure water to a predetermined concentration is used as the processing liquid. In the substrate liquid processing apparatus, the phosphoric acid aqueous solution is heated to a predetermined concentration and a predetermined temperature, and boiled to be used for performing an etching processing.
However, with this alone, it is difficult to secure etching uniformity, and thus improvement is necessary in terms of the etching uniformity.